Step-by-step explanation:
An=A1. R raised to the power n-1
Answer:
18x + 13y = 60
6x + 2y = 6 ---> 6x = -2y +6 ---> 18x = -6y+18
Substitution
(-6y +18)+13y =60
-18 -18
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7y = 42 so y=6
Then, 6x + 2(6) =6, which you will get x = -1
(-1, 6)
Answer:
Step-by-step explanation:
So this is an exponential equation because it is doubling each day.
So you will first determine the equation f (x)
Answer: a - 4.512 hours
b - 1.94 hours
Step-by-step explanation:
Given,
a) A(t) = 10 (0.7)^t
To determine when 2mg is left in the body
We would have,
A(t) = 2, therefore
2 = 10(0.7)^t
0.7^t =2÷10
0.7^t = 0.2
Take the log of both sides,
Log (0.7)^t = log 0.2
t log 0.7 = log 0.2
t = log 0.2/ 0.7
t = 4.512 hours
Thus it will take 4.512 hours for 2mg to be left in the body.
b) Half life
Let A(t) = 1/2 A(0)
Thus,
1/2 A(0) = A(0)0.7^t
Divide both sides by A(0)
1/2 = 0.7^t
0.7^t = 0.5
Take log of both sides
Log 0.7^t = log 0.5
t log 0.7 = log 0.5
t = log 0.5/log 0.7
t = 1.94 hours
Therefore, the half life of the drug is 1.94 hours
